The third International Yoga Day is being celebrated globally on June 21, 2017, in a great enthusiasm. India is playing the leading role in the yoga day celebration and facilitating the process of making yoga popular among all the societies worldwide. The Prime Minister of India Shri Narendra Modi-ji has made all efforts to prescribe yoga for the common man. A national committee under the leadership of Central Council of Research in Yoga and Naturopathy and Morarji Desai National Institute of Yoga, Ministry of Ayurveda, Yoga, Unani, Siddha, and Homeopathy has prepared a common yoga module for regular practice by common man.

The module has been made simpler without diluting the scientific aspects of yoga. The common yoga module contains warm-up exercises, basic asanas, surya namaskar, simple pranayamas, recitations, meditation, and relaxation techniques. As such, there is no religious practice in this yoga module and should be by and large acceptable to all. However, still there are some reservations from some quarters for the practice of yoga and they have apprehension that yoga may be made compulsory for all, yoga is never discriminatory. Therefore, emphasizing that yoga does not discriminate, the United Nations Secretary-General Ban Ki-moon in his message for the first International Yoga Day had stated that “…And yoga does not discriminate; to varying degrees, all people can practice, regardless of their relative strength, age or ability. I discovered this for myself on trying to do my first asana, a tree pose suited to beginners. It took a moment for me to gain my balance, but once I did, I appreciated the simple sense of satisfaction that yoga can bring.” There was overwhelming support from all parts of the world for the first and second International Yoga Day celebrations.

Practice of yoga refines and improves all the body systems and body components: physical, mental, and vital (energy) bodies.[1] Yoga is a pure science and encompasses the systematically designed techniques of practice. In Hatha yoga, the body is stretched through slow movements with which each posture is maintained, which is meant to increase body flexibility. If the body is supple, it remains young. Pranayama, the controlled and conscious breathing exercise, is a curative measure against a variety of physical and mental ailments and increases one's immunity and resistance to diseases.

Yoga promotes relaxation of body and mind. In yoga relaxation techniques, the sympathetic discharge is inhibited, and parasympathetic discharge is facilitated.[2] The relaxation therapies in yoga such as shavasana, meditation, yoga nidra, and pranayama ensure mind–body relaxation and facilitate sympathovagal homeostasis.[3] However, for achieving sympathovagal balance and maximum relaxation, emphasis is given more on pranayama (practice of controlled breathing exercises). Pranayama (prana + ayama) is the controlled breathing, in which the practitioner regulates his breathing (ayama) and concentrates on imbibing cosmic energy (prana) from the atmosphere through breathings.[1] In normal breathing, inspiration is longer and duration of expiration may be less than half of the inspiration. During inspiration, heart rate is more due to less vagal tone, and during expiration, heart rate is less due to more vagal tone (sinus arrhythmia). Taking advantage of this physiological phenomenon of sinus arrhythmia, yogis (yoga luminaries) had practiced pranayama as part of their natural living and lived healthily for centuries and attained a kind of immortality. Yoga is very essential now for human beings as the level of stress is high in social life.

It has been recently reported that improvement in vagal tone is not only essential for stable cardiovascular (CV) health but also essential for maintaining the fitness of the body as a whole, the integral health.[4] Slow pranayamic breathing has also been reported to reduce sympathetic activity and improve sympathovagal balance. The practice of fast pranayama and suryanadi pranayama (right nostril breathing) has been reported to increase sympathetic activity, and practice of chandra nadi pranayama reported to decrease sympathetic activity.[5] Thus, pranayama is directly linked to autonomic activity, regulation of heart rate, and heart rate variability (HRV). Decrease in heart rate physiologically by practice of yoga or exercise improves HRV. Although resting heart rate can vary widely in normal healthy subjects ranging from 60 to 100 beats/min, tachycardia, especially heart rate >75/min, has been reported to decrease HRV, which is an established CV risk. Pranayama is very effective in reducing heart rate and CV risks and in improving CV health.[6]

Asana provides suppleness to the body and pranayama ensures visceral homeostasis (stable organ functions). Practice of asana and pranayama delays aging and prevents degeneration and often prescribed in the treatment of many diseases such as diabetes, hypertension, and heart diseases. Therefore, asana and pranayama should be practiced regularly for promotion of health and prevention and treatment of diseases. Surya namaskar (ten structured steps of salutation to sun) has both asana and pranayama incorporated in it. Each pose of surya namaskar is an asana, and in each step (asana), there is controlled breathing (pranayama). Thus, surya namaskar is practically the combination of asana and pranayama, and it should ideally be part of regular yoga practice.